Have the same issue and with a few different models and brands I've just ordered a few smaller SD cards 4GB and a card holder similar to this from one of our suppliers.
I'm going to make a card per model and since it's easy to swap the sd card on a "naked" Rubber Ducky I think thats the best way of doing it.
The Bash Bunny i've found is a bit slow to start. However, the Bash Bunny is supper easy to swap beteween two payloads and easy to change the payload since it shows up as a usb drive when in "arming mode". Not tested it with BIOS tasks yet. I'll see if I get around to playing with it some if you want to but I'm gonna go with the Rubber Ducky and extra SD-card for my installs.
I can, when I've done the timings of my installs just try it all on the Bash Bunny as well. Might have to open bios manually but the rest will proberly work.
What modells do you work with?
And what is't you want to do in the BIOS?
We have some HP EliteBooks that I PXE-boot in to a MDT-Install, after that I run some settings when they are installed but most is done by the MDT-Install